Evaluation of entomopathogenic nematodes as a management tactic against ambrosia beetles

Ambrosia beetles are a major pest of many deciduous trees in both agricultural and ornamental systems. While several preventative options such as insecticides are available, there are few to no options once galleries have been established. Entomopathogenic nematodes (EPNs) are a potential control strategy that can fulfill this role. In this study, we analyzed the ability for EPNs to control major ambrosia beetle species, Xylosandrus crassiusculus and X. germanus, both in the lab and field. We found that in the lab, all commercial EPN species analyzed (Steinernema carpocapsae, S. feltiae, S. glaseri, S. riobrave, Heterorhabditis bacteriophora, and H. indica) caused mortality to both species, with S. riobrave causing the highest mortality to X. crassiusculus and S. carpocapsae causing the highest mortality to X. germanus. Despite this, no significant mortality was observed in the field. These results indicate that EPNs can cause mortality to ambrosia beetle, but more study will have to be done to make EPNs more viable against ambrosia beetle in the field.